When you place a ball at the top of a hill and it accelerates toward the bottom

of the hill, it probably also experiences both

- and

When a ball accelerates toward bottom it experiences both rolling friction and air resistance.

Explanation:

When the ball rolls from the hill the gravitational force of attraction comes in action and accelerates the ball toward the bottom of the hill. This motion of ball is the rotational motion, rolling friction acts on it due to rotational motion. As the velocity of the ball increases air resistance also starts to have significant effect on its motion. These two forces try to oppose the motion of the ball.